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Outie

In a Killer Sudoku, an outie is a cell that belongs to one of the selected cages, but lies outside the tested house(s). It is used in the 45 rule, a solving technique used for Killer Sudokus. The digit for a single outie can be calculated as follows: 

(sum of selected cages) - (number of tested houses) x 45

image:Innie-outie.png

The green cell r2c6 is an outie for nonet 3. Its value is 13 + 15 + 18 - 45 = 1.

See also

This page was last modified 22:10, 19 February 2007.